[rt-users] User creation failed in mailgateway: Name in use

[Robert]

Hi,

Bugging me for days, I'm sending an email to RT to create a ticket,
the address already exists in the database.

I send it, it fails and I receive back 3 emails
1. "User creation failed in mailgateway: Name in use"
2. "User 'xxx at xxx' could not be loaded in the mail gateway"
3. "RT could not load valid user"

the log output 

Jun 10 11:28:29 eu-support RT: User creation failed in mailgateway: Name
in use (/opt/rt3/bin/../local/lib/RT/Interface/Email.pm:244)

RT_SiteConfig
Set($AutoCreateNonExternalUsers,1);  
Set($ValidateUserEmailAddresses,1);                                                                



Globals->Group privs
        Everyone->CreateTicket, ReplyToTicket
        Privaleged->CreateTicket, ReplyToTicket
        Unprivileged->CreateTicket, ReplyToTicket

this has happened on more than one occasion and ive been through quite a
few possible fixes? and have run out of ideas,

can anyone shed some light on exactly what is going on?

best
Saragan